Methods and apparatus for recovery of hydrocarbons from underground water tables

ABSTRACT

Methods and apparatus for the recovery of petroleum origin hydrocarbons from ground water tables at sites of refineries, oil and gasoline storage and distributing facilities, and the like. Pursuant to the invention, separate liquid handling devices, each in the nature of a vessel or canister and having liquid trapping and ejecting facilities, are employed in a well or wells at the site for separately raising the ground water and liquid hydrocarbons that accumulate on the ground water table, respectively, through which the well or wells extend, under the static pressure of compressed air and free of mechanical pumping action on the liquids. The indicated devices are suspended in the same or adjacent wells that are located at the site, with the ground water handling device being connected to a source of compressed air and piping for carrying away the water to form a cone of depression at the site, and the hydrocarbon handling device being connected to the source of compressed air and a recovery line for separately surfacing and conveying the hydrocarbons flowing into the cone of depression to a point of collection and recovery.

This application is a division of our application Ser. No. 513,264,filed July 13, 1983, now U.S. Pat. No. 4,527,633.

The present invention is directed to methods and apparatus for recoveryof hydrocarbons from underground water tables, for both waterdecontamination purposes and providing a commercially usable petroleumorigin hydrocarbon byproduct as a result of the decontamination of thewater table, and more particularly, to recovery of petroleum originhydrocarbon liquids that have collected underground at the sites ofrefineries and other oil and gas storage and/or dispersement and/orhandling, piping or the like, facilities, where, due to spillage and thelike, the petroleum origin hydrocarbons in liquid form have goneunderground in quantities sufficient to warrant purging of the groundwater table of same and have as a byproduct of the removal operationadequate quantities of the hydrocarbons for processing as needed toprovide a commercially appealing end product.

It is well known that at refineries and other facilities where petroleumproducts are processed and handled, substantial quantities of thepetroleum origin liquids involved (hereinafter some times referred tofor convenience of reference and description as petroleum originhydrocarbons or "hydrocarbons"), are lost into the ground due tospillage and the like. Over a period of time the hydrocarbons involvedtend to seep down into the ground to the ground water table level, andcollect there. As liquid hydrocarbons have a specific gravity that isless than that of water, and they are, generally speaking, immisciblewith water, they form their own liquid table level on top of the groundwater table. While there may be some admixing of the two discrete typesof liquids as the ground water table rises and falls over a period oftime, the liquid hydrocarbons that are under ground tend to remain aseparate and distinct liquid strata on top of the ground water tablehaving water table characteristics that are similar to those of theground water table.

Heretofore such hydrocarbons have been recovered from wells formed atthese locations and extending well down into the water table, by pumpingthe ground water from the well and piping it to a ground level point ofdisposal that is remote from the well, to create a so-called cone ofdepression in the ground water table adjacent the well, with the resultthat the liquid hydrocarbons there located tend to flow under gravitytoward the center of the cone of depression and collects there. Theground water removed to form the cone of depression, known as draw downwater, is conveyed to a disposal or storage site sufficiently remotefrom the well to avoid the water flowing right back into the cone ofdepression that has been created in the ground water table to in effectserve as a collection basin for the hydrocarbons to be recovered.

Apparatus employed for the purpose of recovery of undergroundhydrocarbons at sites of the type indicated have heretofore involvedmechanical pumping arrangements of the centrifugal and other commonmechanical pump types that are suspended in the well in the hydrocarbonsand operated to pump the hydrocarbons from the well to ground level.These prior art approaches have involved number of problems that in thepast made it difficult to recover these hydrocarbons, in quantitiesadequate in quantity and quality to warrant commercial exploitation ofsame, and consequently limited incentives to try to decontaminate theground water table at sites of the type indicated.

For instance, one currently practiced approach is to deliver therecovered hydrocarbon liquids through a filter that tends to plug up alltoo readily. Further, mechanical pumps that are employed are ordinarilyelectrically driven, and since hydrocarbons are highly inflamable, firedanger is an ever present problem. Also, as the hydrocarbons involvedare removed, the pumping speeds have to be changed to be commensuratewith the hydrocarbons remaining to be recovered, which requiresexpensive variable speed drives for the pump equipment involved.

As to the ground water removed to form the indicated cone of depression,it is important that the draw down involved be as little as possiblesince once the ground is contaminated with hydrocarbons, it will retainsome of the hydrocarbons even after the bulk of same have been removed.Thus, where centrifugal and other mechanical types of water pumpequipment are involved for draw down purposes, some type of levelsensing device and expensive variable speed controls would be requiredin order for the equipment to operate properly, and as draw down pumpsare usually suspended near the bottom of the well, a substantial amountof debris will be passing through the pump with resulting high pumpmaintenance requirements.

A principal object of the present invention is to provide methods andapparatus for recovery of petroleum origin hydrocarbons from groundwater tables, that employs as the prime mover for the equipment involvedcompressed air, with the removal of both the draw down water and thehydrocarbons being separately effected, and with the liquid removedbeing effected by a system of valving and controls that effects atrapping of a quantity of the liquids involved, and compressed airejection of same to the ground level, which system is on a time sequencebasis that is readily adjustable, without requiring expensive variablespeed drives or level sensing devices, to change performance as neededto meet changing well conditions.

Another principal object of the invention is to provide methods andapparatus for draw down removal of the ground water at the hydrocarbonrecovery site, that insures that only water will be removed in effectingformation of the indicated cone of depression in the ground water table,and that minimizes moving parts and simplifies operation for troublefree removal of the water that is involved.

Yet another principal object of the invention is to provide methods andapparatus for removal of the hydrocarbons from ground water tables, andin particular from a cone of depression that has been formed in same forthis purpose, which insures that only the hydrocarbon or a maximizedconcentration of same are brought from the well and conveyed therefromfor suitable treatment to provide the desired product reward for ineffect decontaminating the ground water table involved.

Still other important objects of the invention are to provide methodsand apparatus for recovering the hydrocarbons from ground water tablesat sites where hydrocarbons collect underground, in which the movingparts of the apparatus that are exposed to liquids involved are limitedto check valve type flow controls, the presence of electrical controlsand motors in the recovery wells is avoided, compressed air is the primemover for effecting liquid removal from the well and forced flow of sameto points of collection or disposal, mixing of the unlike liquidsinvolved together or with air is avoided, simple time cycle controls areprovided that may be readily changed at the ground surface to meetchanging well conditions, and the hydrocarbon liquids removed are atmaximum hydrocarbon concentration levels for ready treatment as neededto provide a commercially attractive product.

Yet other objects of the invention are to provide methods and apparatusfor removal of hydrocarbons from ground water tables adjacent refineriesand the like in which the liquid removing devices involved for both thedraw down and hydrocarbon recovery functions, are similar but separateand distinct, and that may be made from standard off the shelfcomponents in sizes needed for particular well applications, and thatare economical of manufacture, readily adapted for a wide variety ofwell type and other similar applications, and that are essentiallymaintenance free, and long lived and effective in operation.

In accordance with the present invention, methods and apparatus areprovided for the recovery of petroleum origin liquid hydrocarbons fromground water tables at sites of refineries, oil and gasoline storage anddispersing facilities, and the like, in which the invention is practicedin association with a well or wells that exist or are driven or formedat the site involved, which wells extend well into the ground watertable at that site. Pursuant to the invention, a basic type of liquidtrapping and ejecting liquid handling device is employed for separatelyremoving the ground water and the liquid hydrocarbons, with the deviceemployed for the ground water removal for draw down purposes beingspecifically devised to take in the water adjacent the lower end ofsame, and be disposed adjacent the well bottom to insure that onlyground water is removed by the draw down procedure. The device forretrieving the liquid hydrocarbon, on the other hand, is equipped tohave its intake porting located closely adjacent the top level of theliquid hydrocarbons so that only the liquid hydrocarbons, or a maximizedconcentration of same, are allowed to enter the hydrocarbons recoverydevice. The separate draw down and hydrocarbon liquid recovery devicesare suspended in the same or adjacent wells at the site involved, withthe draw down device being connected to a source of compressed air andground surface level located piping for carrying away the water to aremotely located desired point of disposal, and the hydrocarbon removingdevice is connected to the same or different source of compressed airand a ground level located recovery line for separately conveying theliquid hydrocarbons to the desired point of storage for later recoveryprocessing, such as a tank or the like. The respective devices havecheck valve fluid directional flow controls, solenoid actuated airsupply and venting controls, and operation timing mechanisms, wherebythe draw down device is operated in the timed sequence required tocreate a cone of depression in the ground water table, so that thehydrocarbons lying on the ground water table tend to run or drain undergravity into the cone of depression which is centered on the well inwhich the draw down device is located; the hydrocarbon removal deviceremoves the hydrocarbons with minimumized admixing with ground waterand/or air, and supplies the removed hydrocarbons to the recovery linetherefor, for conveyance to a suitable storage tank or the like to awaitrecovery processing as needed.

At any one site, one or more draw down devices may be employed and oneor more hydrocarbon recovery devices may be employed. Both types ofdevices may be suspended in the same well, and in one embodiment, theseparate devices are integrally united in a composite unit for thatpurpose. On the other hand, a draw down device may be located in a wellthat is appropriately centered at the ground water table, and a numberof the hydrocarbon recovery devices may be separately and individuallydisposed in adjacent wells that are present or formed as needed, butclose enough to the well having the draw down device to be within thedraw down area defined by the draw down device.

Other objects, uses, and advantages will become obvious or be apparentfrom a consideration of the following detailed description and theapplication drawings in which like reference numerals indicate likeparts throughout the several views.

In the drawings:

FIGS. 1 and 2 are diagrammatic vertical sectional views through a welllocated at the site or locale of an oil refinery or the like wherepetroleum origin hydrocarbons in liquid form have accumulatedunderground and in association with the ground water table at that site,showing the ground water table being subjected to draw down shapingadjacent the well and indicating the layer or table of liquidhydrocarbons that is on top of same, with both being shown draining intothe well through its casing, and illustrating in diagrammatic verticalsection the hydrocarbon recovery vessel or canister that is suspended inthe well and operated in accordance with the practice of the inventionto recover the hydrocarbons, and the basic operating equipmentassociated therewith, which is shown largely diagrammatically, with thehydrocarbon recovery vessel in FIG. 1 being shown in its hydrocarbonintake phase, and the hydrocarbon recovery vessel in FIG. 2 being shownin its hydrocarbon discharging or ejecting phase;

FIGS. 3 and 4 are similar to FIGS. 1 and 2, respectively, but illustratethe ground water draw down vessel or canister and equipment associatedtherewith, with the draw down vessel of FIG. 3 being shown in its groundwater intake phase and the draw down vessel in FIG. 4 being shown in itsground water discharge or ejection phase;

FIG. 5 is a diagrammatic vertical sectional view of the hydrocarbonrecovery vessel on an enlarged scale, and partially in elevation, betterillustrating the components parts of a typical embodiment of same, andillustrating one form of liquid hydrocarbon inflow port arrangement inaccordance with the invention in the liquid well environment of FIGS. 1and 2;

FIG. 6 is a fragmental vertical sectional view, that is similar to thatof FIG. 1 with regard to the illustration of the hydrocarbon receivingvessel liquid inflow arrangement, showing on an enlarged scale amodified form of inflow port and float arrangement therefor;

FIG. 7 is a fragmental transverse cross-sectional view on an enlargedscale diagrammatically illustrating the specific nature of the type ofcheck valve that is employed in the liquid receiving and ejectingvessels or canisters of the invention;

FIG. 8 is a view similar to that of FIG. 5, but illustrating the groundwater draw down vessel or canister, diagrammatically, but in somedetail;

FIG. 9 is a view similar to those of FIGS. 1-4, but showing the drawdown vessel and the hydrocarbon liquids recovery vessel applied to thesame well;

FIG. 10 is a diagrammatic and schematic view illustrating the principlesof the invention incorporated in a three well system; and

FIG. 11 is a view similar to those of FIGS. 1-4, showing a modified formof the invention in which the draw down vessel and the hydrocarbonrecovery vessel are integrated in a single unit and applied to a singlewell.

However, it is to be distinctly understood that the specific drawingillustrations provided are supplied primarily to comply with the PatentLaws, and that the invention is susceptible of modifications andvariations that will be obvious to those skilled in the art, and whichare intended to be covered by the appended claims.

GENERAL DESCRIPTION

Reference numeral 10 of FIG. 10 generally indicates an installation inaccordance with the invention which services three adjacent wells 12that are located at the site of an oil refinery or the like to recoverthe petroleum origin hydrocarbon liquids that have accumulated adjacentthe ground water table of the locale involved. The installation could befor a single well or a number of wells that would be suitable forrecovery of the hydrocarbons involved and corresponding decontaminationof the underlying ground water table. Installations made in accordancewith the invention are effected after the property in question has beeninspected and determination is made using conventional techniques toapproximately locate the underground hydrocarbons involved and that overa period of time have accumulated at the level of the ground watertable. The wells 12 may be existing for other purposes or they may beformed for purposes of practicing the present invention, and theirnumber for any given installation, as well as the depth of the wells,the width of the wells, and the spacing of the wells will depend on suchfactors as the porosity of the soil, the nature of the soil at the sitedinvolved, other geological considerations, existing wells that maypresent and are usable to practice the invention, and the specificationsmade by the property owner or his or its technical consultant.

While the wells 12 may be conventional in nature, generally speakingthey should extend depthwise well below the upper level of the groundwater table that is involved, and they should be lined by a suitablecasing 14 which is suitably and conventionally perforated or aperturedas at 15 (see FIGS. 1-4) so that the liquids in the ground can readilydrain through the respective casings into the well.

In the specific installation 10 that is illustrated, each well 12 isprovided with a hydrocarbon recovery vessel or canister 16 and a groundwater draw down vessel or canister 18 which are arranged and suspendedin operating position in one of the manners suggested in FIGS. 1-9, and11 (which will be referred to more specifically hereinafter). Ininstallations where the individual well casings are wide enough toreceive both the vessels 16 and 18, this is what is preferred and isdiagrammatically illustrated in FIG. 9. However, experience has shownthat many installations will either have or will only permit relativelysmall diameter wells and casings therefor, and in such situations therespective vessels 16 and 18 will be applied to single adjacent wellcasings, in the manner suggested in FIGS. 1 and 2, and 3 and 4,respectively.

As diagrammatically illustrated in FIG. 10, the hydrocarbon recoveryvessels 16 are connected by diagrammatically illustrated conduiting 20to a recovery line or pipe 22 into which the recovered hydrocarbons areinserted, while the draw down vessels 18 are connected bydiagrammatically illustrated conduiting 24 to a water pipe or header 26into which the water is passed and conveyed from adjacent the wells 12to a remote point of disposal or storage, as desired.

The respective vessels 16 and 18 are each connected to compressed airsupply line or header 30 that originates at suitable air compressor 32.For purposes of illustration, FIG. 10 shows for each well 12 anauxiliary pipe 34 communicating between header 30 and branch conduit 36for supplying compressed air to vessel 16 via suitable three waysolenoid operated control valve 38, through suitable pressure regulator40, while auxiliary line 34 also communicates with branch line 42 thatsupplies compressed air to vessel 18 via three way solenoid operatedvalve 44 through suitable pressure regulator 46. The respective solenoidoperated valves 38 and 44 are connected to the respective conduits 48and 50 that respectively lead to the respective vessels 16 and 18. Thesolenoid valves 38 and 44 for each well 12 are arranged to alternatelycommunicate the interiors of the vessels 16 and 18 to atmosphere forventing for admission of the liquids to be received in each vessel, thenshift to close off atmospheric venting of such vessels and admit to theinteriors of same compressed air from header 30 to eject from therespective vessels the liquids that have accumulated in same, with theliquid directional flow controls involved for each vessel being checkvalve controlled by way of operation of the special check valvesincorporated therein which are described specifically hereinafter, and,under the control of suitable conventional timers 52 and 54 that arediagrammatically illustrated and that may be suitably applied to controlpanel 56. Timer 52 is shown to comprise a suitable clock mechanism 58having the usual sweep contact hand or arm 60 that moves thereaboutunder the control of the timing mechanism involved, between spacedcontact indicators 62, 64 and 66 that are fully adjustable 360 degreesabout the timing mechanism. Timer 54 may be similarly arranged andcomprises suitable clock mechanism 67 equipped with suitable sweep handor arm 68 serving as a switch arm that moves between contact indicators70, 72 and 74 in a conventional manner. The timers 52 and 54 arerespectively connected to the respective single pole off-on switches 76and 78 to a suitable electrical supply 80 that may be of 110 voltcapacity. The control panel 56 may be located immediately adjacent to awell 12, or at some remote location in a building adjacent the site inquestion, depending on the situation at the installation site.

The timer 52, when switches 76 and 78 are closed and the installation isoperating, controls electrical energization and deenergization ofelectrical conduits 82 and 84, with conduit 82 being connected at eachwell 12 to contact 90 of the respective three way solenoids 38 by therespective connectors 92, while the conduit 82 is connected to thecontact 94 of the same solenoid valves 38, respectively by connectors96. Timer 54 controls the energization of electrical conduits 100 and102 with the conduit 100 being connected to contact 104 of therespective solenoid valves 44 of each well by electrical connector 106,and the conduit 102 being connected to the contact 108 of the samesolenoid valves 44, respectively, by connector 110.

The Liquid Handling Vessels

The hydrocarbons receiving and ejecting vessel or canister 16 is morespecifically illustrated in the diagrammatic showings of FIGS. 1, 2 and5 wherein it will be seen that the vessel 16 comprises sleeve 110 to theupper end 112 of which is fixed in sealed relation thereto the dishedend cap 114, and to the lower end 115 of which is fixed in sealedrelation thereto the dished end cap 116. The sleeve and its end caps 114and 116 define the vessel chamber 118 which in accordance with theinvention receives a quantity of the hydrocarbons to be recovered, andfrom which the received quantity of hydrocarbons is ejected and moved torecovery line 22.

The sleeve 110 and end caps 114 and 116 may conveniently be formed froma suitable plastic material, such as polyvinyl chloride (PVC schedule 40or 80) and secured together by a suitable solvent bonding material thatprovides the leak free relation desired at all the joints between therespective caps and the sleeve 110. These components may also be formedfrom other suitable plastic materials, and might be formed from asuitable steel or other metal if so desired and joined by threading,welding, or flange bolting with suitable seals interposed therebetweenas will be apparent to those skilled in the art.

At the lower end of the chamber 118 a quantity of ballast 120 isprovided, which may be in the form of small stones, or gravel, butpreferably is lead shot on top of which is applied separator plate 122that is proportioned to be in close fitting relation to the internalsurfacing 124 of sleeve 110 and be suitably bonded thereto to seal offthe ballast from the remainder of the chamber 118. The ballast 120 as awhole preferably should have a weight of about twenty pounds, dependingon the volume of chamber 118, experience has shown.

As indicated specifically in FIG. 5, the top end cap 114 of vessel 16 isapertured at 130 to receive tubular member 132 that inside the chamber118 is abutted in congruent aligned relation to elongate tubular member134 and affixed thereto by securing sleeve 136, with the tubular members132 and 134 and sleeve 136 also being formed from one of the plasticmaterials indicated and these parts being suitably bonded together inleak free relation thereto, using suitable solvent bonding cement or thelike.

Tubular member 134 extends down to adjacent the sleeve end 115, thus thelower end 119 of the chamber 118 to form or define the vessel chamberliquid outflow port 140. The sleeve 132, which is anchored in leak freerelation with the cap 114, at its upper end is aligned with check valvedevice 144 that is of the type diagrammatically illustrated in FIG. 7,and which comprises sleeve member 146 that is in end to end relationwith the sleeve 132 and affixed thereto in leak free relation thereto bya suitable collar 148, as by employing suitable bonding technique screwthreading or the like.

The check valve device 144 is of a commercially available type 151 thatis diagrammatically illustrated in FIG. 7 which comprises mountingsleeve 150 that has applied transversely of same in crosswise relationthereto pivot pin 152 on which are hinged a pair 153 of flapper valveplates 154 and 156 that are free to swing oppositely between thevertically disposed liquid flow passing positions of FIG. 7 (with liquidflow being in the direction of arrow 149) and the outwardly inclineddashed lines positions of FIG. 7 wherein they are in flow checkingrelation with the bore 158 defined by the valve device 151 (when theliquid flow direction is opposite that indicated by the arrow 149). Thevalve devices 151 are commercially available from Techno Corporation ofErie, Pa. and are known as the Technocheck Silent seatless check valve.Their flapper members 154 and 156 are contoured about their margins sothat when they are in their outwardly inclined angled positions, due tothe static pressure of the liquid flow that is directed toward therespective free ends 155 and 157 (that is, unpwardly in the showing ofFIG. 7), they are in liquid flow checking relation with the bore 158 ofthe sleeve 150, and when the liquid flow is in the opposite direction,the static pressure of the liquid flow swings the flapper members 154and 156 to the substantially parallel, flow passing relation shown inFIG. 7. Similarly, when there is no flow in either direction, theflapper members 154 and 156 take a similar substantially parallelposition under the action of gravity, assuming the sleeve 150 in theposition shown in FIG. 7 is vertically disposed or substantially so.Thus, the flapper members 154 and 156 are journalled on the hinge pin152 for free swinging movement relative thereto, and they are free fromspring biasing in either direction of movement. It is the direction ofliquid flow past the flapper members 154 and 156 that positions them ineither flow checking or free flow passing relation. The Technochecksilent seatless check valve arrangement that is diagrammaticallyillustrated by the showing of FIG. 7 is available in various sizes andmaterials and for connection to adjacent parts by bonding, screwthreading, flange and bolt connections, or any other suitable manner, asneeded or desired for a particular installation.

The basic check valve device 151 in application may be disposed asindicated in FIG. 4, with the flapper members 154 and 156 in dependingrelation, or may be disposed in the oppositely oriented verticallydisposed relation, depending upon the application. Where the applicationcalls for the liquid, the flow of which is controlled by the valvedevice 151, to be continuously within the valve sleeve bore 158, thevalve device 151 may be other than vertically disposed, as, forinstance, horizontally disposed, since the direction of the liquid flowwill control the opening and closing of the flappers 154 and 156. Thevalve device 151 thus comprises a pair of oppositely acting andnon-spring biased flapper members 154 and 156 mounted for full freeswinging movement about a common pivot axis represented by cross pin152, that extends crosswise of the direction of the liquid flow throughthe valve device in question. In the flow permitting mode of the checkvalve, the flapper members are in folded substantially parallel side byside relation in which liquid flow is permitted in the direction theflapper members extend from pin 152, while in the flow checkingrelation, the flapper members 154 are in the indicated oppositely angledrelation wherein their margins are seated against the surface 159 of thesleeve that defines bore 158 with the margins of the flapper members 154and 156 conventionally being configured for seal tight fit relation withthe sleeve bore defining surfacing 159 in the commercially availableembodiments of same.

Referring back now to FIG. 5, it will thus be seen that the check valvedevice 144 is in the form of check valve device 151 of FIG. 7, butdisposed 180 degrees from the showing of FIG. 7. Suitably fixed, as byscrew threading, to the upstanding end of the valve sleeve 146 issuitable nipple 170 over which one end 172 of flexible hose or piping174 is affixed, as by employing the suitable force fitting relationindicated in FIG. 5, or any other suitable leak free connection such asthat provided by the use of conventional hose clamps. The other end 176of the flexible hose or piping 174 is suitably connected to stand pipe178 that is suitably connected to and rises from the hydrocarboncollector conduit or piping 22; for this purpose, the flexible piping orhosing 174 may be provided with a conventional coupling 180 that has afamiliar form of screw threaded and sealed connection to the upper endof stand pipe 178. It will thus be apparent that the flexible piping orhosing 174 and stand pipe 178 form the diagrammatically illustratedconduiting 20 of FIG. 10.

The vessel or canister 16 is adjustably supported within the well 12 towhich it is applied, by suitable winch 184 (equipped with operatinglever 185), that is appropriately mounted on top cover structure 186 ofwell casing 14, to which is operatively connected supporting cable 188that extends through an aperture 190 formed in the cover structure andis connected to basket structure 192 in which the vessel or canister 16is mounted. Cover structure 186 may be suitably locked or clamped inplace on the casing, as by employing suitable hold down or clampingdevices 454 that are diagrammatically illustrated in FIG. 9. The basket192 may be of any suitable type, that illustrated comprising a pair ofstrappings 194 and 196 formed from suitable webbing or the like,stitched together as at 198 that forms the bottom of the basket andhaving the ends 198 and 200 of the strapping 196 suitably applied toring 202 to which the lower end 204 of the cable 180 is suitablyapplied, as by having an "eye" formed in same for this purpose or someother conventional connector device being provided. The strappings 194and 196 are connected by a pair of upper and lower transversecircumferential strappings 206 and 208, as by employing suitablestitching techniques so that the strappings 194 and 196 define theaforeindicated basket 192 in which vessel 16 is disposed for adjustablesuspending in the well from winch 184.

Slidably mounted on the cable 180 is a tubular float member 210 that maybe formed from a suitable plastic material or the like and definesintegrally united outer and inner cylindrical side walls 212 and 214 andtop and bottom end walls 216 and 218 which form an annular closed offchamber 220 in which air is trapped, and a bore 222 located along theaxial center of same through which the cable 180 extends. Fixed to theouter side wall 212 of float member 210 is sleeve 224 that forms thehydrocarbon inlet 225 for vessel 16, with both the float 210 and sleeve224 being formed, for instance, of suitable plastic materials and fixedtogether by a plastic strapping 226 wrapped thereabout and bondedthereto employing a suitable bonding cement or the like or alternatelyemploying a suitable conventional hose clamp for this purpose. The upperend 228 of the sleeve 224 is preferably disposed well below the top end216 of the float member 210, for reasons that will be made clearhereinafter, and is in the nature of a wier that defines inlet 225.

The sleeve 224 has suitably bonded to the lower end 230 of samelongitudinally extensible and contractible conduiting 232 that may beformed from a plastic material having a suitable convuluted or pleatedconfiguration for this purpose, with the lower end 234 of the conduiting232 being applied in force fitted relation to the upstanding end of acheck valve device 236 that is of the type shown in FIG. 7 and havingthe positioning orientation shown in FIG. 7, with the sleeve 238 of thedevice 236 suitably bonded to the vessel top cap 114 in leak freerelation thereto.

Referring now to FIGS. 3 and 8, the draw down vessel or canister 18 isof generally the same basic type of construction as the vessel orcanister 16, but is preferably of greater volumetric capacity, and thusis longer since both vessels 16 and 18 preferably are made toapproximately the same diameters. Vessel 18 generally comprises elongatesleeve 240 having suitably fixed to its upper end 242 end cap 244. As isthe case in connection with the vessel 16, the vessel 18 has itsprincipal components formed from a suitable plastic material, such asthe aforementioned PVC, with the top cover 244 being of dishedconfiguration and suitably mounted in leak free relation to the upperend 242 of the sleeve 240 employing a suitable bonding solvent. Thelower end 246 of the sleeve 242 has affixed to same a check valve 248 ofthe type 151 shown in FIG. 7, with the valve 248 disposed in avertically opposite position to the showing of FIG. 7 and having anannular side wall 249 substantially the same size as and aligned withthe lower end 246 of the sleeve 240 and affixed thereto by anchoringsleeve 250; for this purpose the side wall 249 of the check valve 248 isformed from the indicated PVC material and sleeve 250 is bonded in leakfree relation to both the sleeve or shell 240 and the side wall 249employing suitable solvent bonding materials. As indicated in FIG. 8,the shell 240, cover 244, and check valve side wall 249 define a vesselchamber 252 that is open at the lower end 254 of same except when closedby check valve 248. The check valve side wall 249 is formed with a pairof oppositely disposed cross apertures 256 and 258 in which is securedcross bar 260 (as by employing suitable cement), the opposite ends 262and 264 of which protrude outwardly of the vessel to serve as supportsfor a suitable connector 266 formed from wire or rope or the like andanchored at its ends to the bar 260, and supporting a box 268 containinglead shot 269 or the like by way of suitable links 270 and 272, or thelike, whereby the vessel 18 is likewise provided with a ballast on itslower end. The ballast may also be formed by a block of cement or stoneor the like, and the ballast of box 268 should have a weight in therange of from about ten to about one hundred pounds, depending onconditions, and the size of vessel 18 employed for any particularinstallation. The vessel 18 carries tubular member 280 that iscomparable to the tubular member 134 of vessel 16, and which defines thevessel outflow port 282 at the lower end of same. The tubular member 280adjacent to its upper end 284 is affixed to the vessel top cover 244 inthe same manner that tubular member 134 is secured in place, asindicated by corresponding reference numerals. The tubular member 280thus has secured thereto check valve device 286 that is of the type 151indicated in FIG. 7, and that is oriented in the same manner as thecheck valve device 144 of FIG. 5. Check valve device 286 has nipple 288suitably affixed to same that receives in sealed relation thereto thelower end 290 of flexible piping or hosing 292, in the same manner asindicated for vessel 16. Piping or hosing 292 at its end 294 is suitablyconnected to stand pipe 296 that is in turn connected to the waterdischarge enter or conduiting 26. The flexible hosing end 294 may beequipped with the suitable fitting 298 for this purpose, to provide aconventional screw threaded seal connection to the stand pipe 296, or asimilar connection of any suitable type that will provide the sealconnection needed, as will be obvious to those skilled in the art. Thepiping 292 and standpipe comprise the diagrammatically illustratedconduiting 24 of FIG. 10.

Vessel 18 in use is also applied to a suitable basket structure 300,that illustrated comprising a pair of strappings 302 and 304 (see FIG.8) of the same type as the corresponding basket strappings for vessel16, suitably stitched together as by 306, and reinforced by transversecircumferential strappings 308 and 310 that are also suitably stitchedin place. The ends 312 and 314 of the strapping 304 are suitablyconnected to anchor ring 316 to which the lower end of cable 318 thatsuspends the vessel 18 in the well is applied. As is the case with thecable 188 of the vessel 16, the cable 318 for vessel 18 is suitablyapplied to winch 320 that is mounted on the well casing top coverstructure 322 for this purpose, with the cable 318 passing throughsuitable aperture 324 formed in the cover structure 322 for thispurpose. As is the case for cable 188, the winch 320 may be of anysuitable type, that illustrated being the hand operated model 1000 thatis offered commercially by Dutton-Lainson Co. of Hastings, Nebr., andthat is provided with hand crank arm 323 for adjustment purposes andsuitable braking means to hold the respective vessel, in the desiredposition of adjustment.

As has been previously indicated, the invention contemplates that thechambers of the vessels 16 and 18, when charged with liquid, will bedischarged by employing an ejecting action on the liquid through the useof compressed air, under the control of the system diagrammaticallyillustrated in FIG. 10, including the timing mechanisms that have beenindicated, the solenoid operated three way control valves 38, and thepressure regulating devices 40, as well as the associated conduitingthat is diagrammatically illustrated.

With regard to the vessel 16, in the showings of FIGS. 1 and 2, thepressure header 30, for each well 12, is shown to have a stand pipe 330connected thereto that at its upper end 332 includes conventional elbow334 to which the air pressure control regulator 40 is connected forsupplying air pressure under a predetermined psig to the solenoidoperated three way control valve 38, the operation of which iscontrolled by timer mechanism 58. Flexible flow conduit 336 has itsupper end 338 suitably connected to the three way control valve device38, and its lower end 340 suitably connected to conventional fitting 342that is in leak free sealed relation with the top cover 114 of vessel 16(not shown in FIG. 5).

The three way control solenoid operated devices 38 and 44, the airpressure regulators 40 and 46, and the timer devices 58 and 67, may beconventionally available devices. For instance, the three way valvedevice 38 may be one of the ASCO three way solenoid valves made and soldby Automatic Switch Company of Florham Park, N.J., such as thatcompany's model Nos. 8316 or 8317, with the two alternate positions ofthe three way valve being indicated in FIGS. 1 and 2, whereby theposition of FIG. 1 the valve 38 is to vent the vessel chamber 118 toatmosphere through conduiting 36 and close same off from the airpressure of header 30, while in the position of FIG. 2, the valveventing aperture or orifice is closed off and the chamber 118 of vessel16 is connected to the pressure of the header 30 through air pressureregulator 40. Valve 38 is basically a housing having a spring biasedplunger which is magnetically to one position when energized (forinstance the position illustrated by the showing of FIG. 1), and springbiased to the opposite position when the solenoid is deenergized (theposition of FIG. 2).

The pressure regulators 40 and 46 may be the Speedair Air PressureRegulator offered by Dayton Electric Manufacturing Co. of Chicago, Ill.,which can be adjusted to give any air pressure desired. The model numberto be used will depend on the size of the device needed in view of thedepth of the well in question, the length of the air line 336 and thehead against which the air under pressure is to be supplied to thevessel.

The timer mechanisms 58 and 67 may be the Eagle Time Miniflex Seriesindustrial control device offered by Eagle Signal Division of GulfWestern Industries Inc. of Austin, Tex. and Davenport, Iowa (such asModel No. DA100). These devices are solid state on/off repeat cycletimers using integrated circuits for timing function. However, anysuitable adjustable on/off type timer could be employed for this purposeincluding those that are controlled by fluids or mechanisms such asmechanical clock mechanisms.

As to the vessel 18, as indicated in FIGS. 3 and 4, the header 30 isprovided with a separate stand pipe 350 having an elbow 352 at its upperend which is connected to pipe 354 that is in turn connected to pressureregulator device 46 that supplies air at the desired pressure to threeway control valve 44 that operates under the control of timer mechanism54. The control valve 44, the regulator 46, and the timer device 54 maybe of the same type as the corresponding control valve 38, pressureregulator 40, and timer device 58 that are provided in connection withthe vessel 16.

Suitable fluid flow conduit or connector 356 has its upper end 358suitably connected to three way control valve 44, and its lower end 359suitably connected to conventional fitting 360 that is affixed to theend cap 244 of vessel 18 in any suitable manner in leak free relationthereto for venting the chamber 252 to atmosphere through valve 44, andalternately supplying air pressure to chamber 252 from header 30 throughpressure regulator 46 and valve 44 to eject liquid received in thechamber 252 from same.

The length of the flexible hosing or piping that are to form theconduits 174 and 336 for the vessel 16, and the corresponding hosing orpiping 292 and 356 for the vessel 18, will depend on the depth of theground water table at any particular well site, the amount of draw downthat is to be provided for, and the like, and in addition, three to fivefeet or so additional footage should be provided for to provide foradjustment to take care of any fluctuations that are incurred duringoperation of the installation.

In the showings of FIGS. 1 and 2, the stand pipe 330 and associatedpiping are diagrammatically represented in FIG. 10 by conduiting 34 and36, while in the showing of FIGS. 3 and 4 the stand pipe 350 andassociated piping are represented in FIG. 10, by conduiting 34 and 42.Flexible connectors 336 and 356 of FIGS. 1 and 3 are represented in FIG.10 by conduits 48 and 50 respectively. The well casing covers 186 and322 are suitably apertured to pass the piping 174 and connector 336 ofFIGS. 1 and 2, and the piping 292 and connector 356 of FIGS. 3 and 4,respectively.

Operation of Installation

In practical application, in readying an installation or installationsfor practicing the invention at a particular refinery site or the like,the area involved requires careful inspection and study for itsunderground characteristics to determine the existing level of theground water table, the amount of hydrocarbons in association with thesame, the nature and characteristics of the soil and other geologicalaspects involved, and the like. Where wells comparable to wells 12exist, they will be very helpful in determining the information needed,and it may be necessary to drive or form one or more additional wells,and in all instances, a casing such as casing 14 needs to be provided toshore up each well, and as indicated, the casing should have a multipleof suitable apertures 15 in spaced apart relation along the height ofthe casing to provide for free flow of the liquids involved into thewell. In some cases, where the site involves a barrier trench, as atgasoline stations and the like, the well casing may be disposed in thetrench and held in place by gravel backfill, to define a well 12.

As indicated, where the wells 12 are to be of smaller diameter due tothe conditions encountered or specified in setting up the installation,the vessels 16 and 18 are applied to separate wells. Where the wells canbe of a larger size to accommodate both vessels in the same well, thenthe approach indicated in FIG. 9 is employed.

Where the wells are proportioned to receive only a vessel 18 or a vessel16, a vessel 18 may be applied to a centrally located well 12, and oneor more adjacent wells 12 that will be within the cone of depressionprovided by the operation of vessel 18 may each have a vessel 16 appliedthereto. The size of the cone of depression in terms of the spacing ofits circumference from the vessel 18 creating same will depend on thewater handling capacity of the vessel 18 in question, the porosity ofthe soil involved, and the land owner's needs and requirements forhydrocarbon recovery from the installation site involved.

In any event, the air header line 30 and the water header or convey awayconduit 26, as well as the hydrocarbon liquid recovery line 22, are alllocated adjacent the ground surface, and preferably are applied justbelow the ground surface and covered for protection purposes, assuggested by the showings of FIGS. 1-4 and 11. These conduits for eachwell are laid out in the manner diagrammatically indicated in thedrawings, with the respective specific pieces of conduiting used forconnection to the air compressor, the water carry off conduiting orheader, and the hydrocarbons recovery piping being connected as neededfor the air pressure supply purposes, the ground water carry awaypurposes, and the hydrocarbons recovery purposes contemplated by thepresent invention, as has been explained.

In the showings of FIGS. 1-4, the ground water table is indicated byreference numeral 380, with its upper surface level being indicated byreference numeral 382. The body of petroleum origin liquid hydrocarbonsthat is to be recovered, generally speaking, forms its own table asindicated at 384, on top of the ground water table 380, with the upperlevel of the hydrocarbons being indicated by reference numeral 386.

Assuming an installation such as that indicated in FIGS. 1-4 (assupplemented by FIG. 10), in which a given well 12 has a vessel 18applied to same, and an adjacent well 12 (which should be in the cone ofdepression created by the vessel 18 in question) as already indicated,has a vessel 16 operating therein, the respective vessels are operatedin the alternate manners indicated in FIGS. 1 and 2, and 3 and 4. Thesame manner of operation is involved for the respective vessels 16 and18, regardless of whether there are only two wells with one well havinga vessel 16 and the other well having a vessel 18, or where one well hasboth a vessel 16 and a vessel 18 (as indicated in FIG. 9) or a series ofadjacent such wells, or where a single well has a vessel 18 applied tosame, and a plurality of wells are formed about the single well inquestion, in radially spaced relation thereto, and each has a vessel 16applied to same.

In any event, the vessel 18, (which is to serve the draw down functionsof the invention), which for any given well in which it is employed issuspended by cable 318 that is connected to the basket 300 for same, islowered to be closely the adjacent the bottom of the well, and as amatter of fact it is preferred that the ballast 268 be rested on or beclosely adjacent the bottom of the well. This insures that only groundwater is removed from the well by the vessels 18.

The vessels 18 that are employed in a given installation are set intooperation under control of timer 54 so that they alternate between thepositions shown in FIGS. 3 and 4 to provide for charging them withground water to any desired capacity and then discharging therefrom thewater charge in question into carry off header 26. In the operativerelation shown in FIG. 3, the three way control valve 44 is positionedto vent the vessel chamber 252 to atmosphere through conduit 356, andthe static pressure of the ground water disposes the flapper members 154and 156 of check valve 248 in their folded, substantially parallelrelation to freely admit the ground water into the chamber 252, whichstatic pressure expels the air within the chamber 252 to atmospherethrough the conduit 356 and valve 44. When the chamber 252 is filled orfilled as desired with a charge of ground water, the position of thethree way valve 44 is reversed by the action of timer 54 to admitcompressed air from the header 30 through the three way control valve 44and conduit 356 to expel the ground water received in the chamber 252through outlet port 282, tube 280, and the check valve 286, throughconduiting 292 into the ground water and carry off header 26, whichheader should carry the water to a point of storage or other disposalthat is at a remote location from the wells being treated by theinstallation in question.

As indicated, the function of the vessels 18 and their conduiting andcontrols is to receive and trap the ground water charge in same, and toeffect removal of the water from the ground water table level and intoand through header 36 at a rate which is adequate to form the cone ofdepression that is diagrammatically illustrated at 390 in FIGS. 1-4.What this involves is that the water is being removed from the well at asufficient rate timewise so that the ground water table adjacent thewells having vessel 16 disposed therein is depressed downwardly so thatthe body 384 of hydrocarbons on top of same tends to gravitate into thewell and form a body 391 of recoverable liquid hydrocarbons within thewell casing 14 that is involved. Experience has shown that for mostapplications, adequate ground water draw down can be provided for byeffecting ground water removal in the range of from about twenty gallonsper minute to about one hundred twenty-five gallons per minute, thoughat some installations, where ground water presence is high the waterremoval rate might be in the 125 to 225 gallons per minute range, whereexcess water is involved, as for instance, from underground springs andthe like. For any particular installation, the vessel chamber 252 issized volumewise to provide for the ground water removal rate needed forthat particular installation.

In any event, the timer device 54 is conventionally arranged to be setto operate the vessels 18 and associated parts at the time sequence ratethat will provide the water charging and removal rate which will formthe cone of depression that is desired for any given installation sothat at the same or adjacent wells having the hydrocarbons recoveryvessels 16 disposed in same, the hydrocarbons will collect to form theindicated body 391 of same. In the diagrammatic illustration depicted byFIGS. 3 and 4, when the timer mechanism 54 has its control arm 68 set atcontact indicator 70, the control valve 44 is disposed by, for instance,the solenoid involved in its arrangement (as referred to hereinbefore)in its vent position, in which ground water from the bottom of the wellenters the chamber 252 and displaces the air therefrom through valve 44.The function of check valve 286 (which is diagrammatically indicated inFIGS. 3 and 4) is to prevent any liquid in the conduit 292 above valve286 from entering the chamber 252 during this period. As time goes by,the indicator arm swings over to the contact indicator 72, at whichpoint the position of the solenoid valve reverses (for instance, bydeenergization of the solenoid and under the biasing action of the valvespring), to set the components involved in the position indicated inFIG. 4, in which the valve 44 closes the chamber 252 against venting tothe atmosphere, and compressed air is supplied through regulator 46 andvalve 44 to chamber 252. As indicated, the regulators 46 arecommercially available and adjustable to provide any uniform or constantpressure output to the valve 44 and vessel chamber 252 that is desiredor needed in terms of psig. Normally this pressure will be in the rangeof from about 10 to about 200 psig, depending on operating conditions,including the fluid head that the chamber 252 is subjected to.

In any event, the air pressure acting on the liquid within the chamber252 exceeds the static pressure of the water acting on check valve 248,which disposes its flapper members 154 and 156 in the flow blocking,angularly related, liquid charge trapping, positions, shown in FIGS. 4and 8, while the check valve 286 changes position to the outflowpermitting relation indicated in FIG. 7, whereby the ground water isejected from the chamber 252 through outlet port 282, tubular member280, and into flexible conduit 292 and thence to header 26. In theshowing of FIG. 4, the timer device 54 has progressed to near the end ofthe emptying cycle for vessel 18. When the swing arm 68 of the device 54reaches the position of contact indicator 74, the timer device isconventionally arranged to automatically resets it to the positionindicated in FIG. 3, wherein the position of the solenoid operated valve44 is again switched to its air pressure blocking and vessel chamberventing relation that is indicated in FIG. 3 (it being conventionallyequipped for this purpose). Thus, the operation of the apparatusinvolved between the contact indicators 70 and 72 represents the fillingcycle of the vessel 18, while the operation of same between theindicators 72 and 74 represents the emptying cycle of same.

With the operation of the vessel or vessels 18 having proceeded to thepoint where the cone of depression 390 is present at the wells beingtreated in accordance with the present invention, the vessels 16 are putinto operation. As indicated in FIGS. 2 and 3, the vessels 16 aresuspended within the wells 12 to which they are applied to locate theupper ends 228 of their intake port defining sleeves 224 closelyadjacent the level 394 of the body 392 of the hydrocarbon liquids thatare within the well casing 14, on top of the ground water that is alsoin same. In this connection, the upper end 228 of the sleeve 224 shouldbe disposed a short distance beneath the level 394, such as no more thanabout one half inch with the sleeve 224 being fixed to the float 210 toprovide such spacing, and the float 210 is intended to have its upperend above the surface 394 a sufficient amount so that it can be readilyviewed from the top of the well casing. This insures that the highestconcentration of the hydrocarbon liquids will be admitted to the vessel16, and will avoid the intake of any air. While there will be somemixing of the hydrocarbon liquids with the ground water that hasoccurred over a period of time due to the rising and falling of theground table and other factors, adjacent the top level or surface 394 ofthe body 392 the hydrocarbons will be either free of water or in acondition of maximized freedom from water content.

With the winch 184 appropriately set to so suspend the vessel 16 in thewell 12 as indicated, the timer mechanism 58 is operated to put thevessel through its filling and emptying cycles, it being conventionallyarranged to so operate in the same manner as identical timer mechanism54, but in a range that is appropriate for recovery of the hydrocarbonliquids, as distinguished from the range required for vessels 18 to formthe indicated cone of depression. Thus, when the timer mechanism 58 theits arm 60 at the contact indicator 62 position, the three way controlvalve 38 has the positioning indicated in FIG. 1, wherein the vesselchamber 118 is vented to atmosphere through the flexible conduit 336 andvalve 38, and check valve 236 is in its liquid flow permitting positionas indicated in FIGS. 5 and 7, whereby the liquid hydrocarbons enter theopen end 228 of sleeve 224, and descend through the flexible conduit 232through valve 236 into chamber 118. Air displaced from chamber 118 bythe entry into same of the liquid hydrocarbons passed the check valve236 passes through conduit 336 and valve 38 to atmosphere. The checkvalve 144 at this stage is in its closed position, to which its flappermembers 154 and 156 gravitate, and should there be liquid hydrocarbonsin conduit 174 upstream of valve 144, it serves its check valve functionat this stage in preventing reentry of same into the chamber 118.

When the timer mechanism swing arm 60 has moved to its contact indicator64 position, the fill cycle ends and the emptying or hydrocarbonsexcavation cycle starts, which involves the three way valve 38 switchingto its indicated position wherein venting to atmosphere of chamber 118is closed and compressed air is admitted through the valve 38 to chamber118 through conduit 336. The static pressure of the compressed airacting on the liquid hydrocarbons now in the vessel chamber 118 effectsa closing of the check valve 236 to preclude discharge of thehydrocarbons through same, and opening of the check valve 144, wherebythe compressed air ejects from the chamber 118 the liquid hydrocarbonsthat have been received and in effect trapped in same. The regulator 40,as already indicated, is adjusted to suit conditions to provide thedesired constant air pressure for evacuating the liquid hydrocarbonsfrom the chamber 118. In the showing of FIG. 2, the timer mechanismswing arm 60 has progressed to closely adjacent the contact indicator66, so that it is well into the empty cycle of the vessel 16 involved.At the end of the empty cycle, at which the swing arm 60 is aligned withthe contact indicator 66, the timer mechanism by reason of itsaforereferred to conventional arrangement automatically resets to theposition indicated in FIG. 1 to repeat the filling and emptying cyclesof the vessel 16. The air pressure made available by regulator 40 forapplication to the liquid hydrocarbons in the vessel 16 to effect theemptying stroke, and the timing of the operation of the apparatusinvolved should provide for removing the liquid hydrocarbons at a ratein the range of from about one gallon per minute to about five gallonsper minute, depending on conditions at the well site, including thefluid head acting on chamber 118. As indicated, the liquid hydrocarbonsduring the vessel empty cycle are ejected through the vessel outlet port140, through tubular member 134 past the now opened check valve 144,through conduit 174 and into the hydrocarbon liquid recovery line 22where they, together with the other liquids supplied to line 22 by theother vessels 16 that are operating, are conveyed to a suitable remotelylocated storage tank or the like to await processing as needed torestore their commercial viability.

The ballast for both vessels 16 and 18 is provided to stabilize them andenable them to be submerged in the liquids in both the full and emptystates of the vessels. The ballast may be made up of any suitable deadweight material, such as lead shot, stones, cement, or the like.

Where the vessels 16 and 18 are both applied to the same well, asindicated by the showing of FIG. 9, their related components andequipment, the connections involved, and their manner of operation isthe same as has already been described.

The vessel 18 may also be employed to control the level of the uppersurfacing of the ground water table and the liquid hydrocarbons that areadjacent and lying on same. This may be done by disposing the vessel 18so that the normal ground water upper surface 382 and the normalhydrocarbon liquids upper surface 386 are intermediate the upper andlower ends of vessel 18, and then operating the draw down equipmentinvolved to effect a gallon per minute ground water removal action thatapproximately equals the flow of the ground water and liquid hydrocarbonliquids into the well. As the volume of the vessel chamber 252 is sizedin accordance with the ground water removal rate found necessary toeffect adequate draw down at the site in question (as hereinbeforedisclosed), by operating the thus positioned vessel 18 in question forground water removal purposes at the same cycles per unit of time withthe result that the gallon per minute water outflow is a fraction of therated vessel capacity (for instance, one half, where the vessel ispositioned so that its chamber 252 will be filled only one-half itscapacity during its "fill" cycle), the indicated level controllingground water removal action will be in effect. This method of operationof the draw down vessel 18 permits the establishment of a ground watertable level that is substantially constant as long as the draw downvessel 18 operates in the manner indicated, and the ground waterconditions at the site in question remain approximately the same.

In the embodiment of FIG. 11, a composite vessel assembly 400 isillustrated, in which the upper vessel is a hydrocarbon trapping andejecting vessel 16A defining hydrocarbon receiving chamber 18A. Thevessel 18A, instead of having lower end wall 115, is affixed to theannular angle member 402 that is in turn affixed to separator plate 404.The vessel section 18A that defines the ground water receiving chamber252A, instead of having the upper end cover 244, has the sleeve or sidewall 240 affixed to a second angular member 408 that is in turn affixedto the divider plate 404. These components may all be formed from theindicated PVC material and fixed together in leak free relationemploying suitable bonding cement or the like.

The composite mechanism 400 is received in a suitable basket 410 that iscomparable to the respective baskets 194 and 300 for connection to, forinstance, cable 318 of a winch 320. The hydrocarbons receiving vessel16A is otherwise arranged essentially as indicated in FIGS. 1, 2, 5 and7, including the venting and compressed air connections to same, whilethe corresponding connections of the draw down vessel section 18A areextended in leak free relation through the sleeve 240, with comparablecomponents being indicated by reference numerals that are the same asthose employed for corresponding components in FIGS. 1-4, 5 and 7,respectively, as are the connections for same. Since one well 12 isoperated on in the showing of FIG. 11, the compressed air may besupplied to the respective vessels 16A and 18A from a commcn header 30that serves both three way valves 38 and 44, as indicated in FIG. 11.

In the modification of FIG. 6, an alternate form of liquid hydrocarbonsintake combination float and intake port device 420 is illustrated inwhich the spherically contoured hollow float 422 is anchored by asuitable stem 424 to a cross plate 426 has secured across the reduceddiameter discharge portion 428 of a floating wier 430 that definesannular circumambient side wall 432 within which the float 422 iscentered, with the float 422 having the requisite bouyance to hold thewier 430, and namely the upper edge 433 of its side wall 432 just belowthe level 394 of the liquid hydrocarbons that are within the well beingserviced by a vessel 16. The wier discharge end 428 has suitably affixedto same by the screws 436 that secure the cross bar 428 in place asuitable fitting 438 having a depending end portion 440 to which theupper end of the flexible conduiting 232 is connected, as by employingsuitable clamp device 442.

The float devices illustrated for the embodiments of FIGS. 5 and 6 areprovided so that the inflow port of the vessel 16 that is employed, asdefined by a sleeve 224 or the wier 430, remains at the indicatedpredetermined distance below the top surface 394 of the hydrocarbonliquids, with the longitudinal, expansible and contractable flexibleconnector 232 extending and contracting as the level of the hydrocarbonsliquids varies relative to the location of the vessel 16 served by same.The thickness dimension "h" of the hydrocarbon liquid that is in effectskimmed off the hydrocarbon body 391 may be controlled by adjustablythrottling the venting to atmosphere through valve 38, and preferablydownstream of the valve 38 venting discharge port 450, as by employing asuitable venting orifice or passage adjustable throttling device of anyconventional type.

It will therefore be seen that the invention provides methods andapparatus for recovery of petroleum origin liquid hydrocarbons fromground water tables, thereby in effect decontaminating the ground water,and has a number of advantages.

For instance, with regard to the components of the apparatus that are tobe submerged in the liquids, there are no moving parts except for thedouble flapper type seatless check valves, the opening and closing ofwhich are in response to the direction of fluid flow past same, and thestatic pressures on either side of same. Further, there are noelectrical controls or electrically operated motors to be located ineither the well or the casing therefor. The only electrical equipmentinvolved that may be adjacent the well is the solenoid actuated threeway control valve and timer controls therefor, which are located outsidethe well, and can be remotely located if so desired.

The prime mover for ejecting the trapped liquids from the respectivevessels is compressed air, and the source of compressed air may becentrally located with regard to the installation site in question, forease of maintenance and reduction of costs. At many sites where thisinvention is applicable, a source of compressed air already exists,which avoids the need for installing expensive electric motors andcompressors to operate air compressors.

The timing of the liquid receiving and ejecting vessels, in operation,is readily changed to meet changing well conditions. As indicated, thetiming devices for controlling the fill and emptying cycles of thevessels can readily be adjusted to provide any time of operation desiredfor either cycle. While those specific timers referred to are preferred,any suitable off-on type adjustable timer will be satisfactory. Thisarrangement avoids the need for having liquid pumping equipmentfurnished with expensive variable speed drives.

As it is important to draw down the water table level as little aspossible, since once the ground is contaminated with oil, it will remainto a degree contaminated, the use of one of the draw down vessels 18 asa liquids level control device insures positive level control, wherethis is desired, without requiring the use of expensive level sensingdevices of a conventional nature.

The floating hydrocarbons intake arrangement permits the intake port ofthe hydrocarbons receiving and ejecting vessel to have intake of thehydrocarbons from closely adjacent to the top surface or level of same,which allows only the highest concentration of the hydrocarbons to enterthe vessel. Use of centrifugal pumps or the like with an intakesimilarly located could be expected to draw air into the pump resultingin damaging cavitation.

Furthermore, the hydrocarbons as well as the ground water are in effectextracted from within the well and lifted or shifted to ground level andcarry away conduiting therefor without any agitation of the liquidsinvolved. It sometimes is the case that the hydrocarbons have some watermixed in with it, and which when such a mixture is pumped by centrifugalpumps or the like the oil and water is emuslified, making separation ofthe pump product difficult.

As has been pointed out, the draw down vessels can be placed closelyadjacent the bottom of the well for intake of liquids that arecontamination free water. The shaping of the draw down vessels adaptsthe vessel lower end for close spacing with regard to the bottom of thewell, and this arrangement is not available with conventionalcentrifugal pumps that might be used for the same purpose. Further,since the draw down vessel has essentially no moving parts other thanthe very simplified check valve arrangements referred to, maintenancerequirements are minimal, as distinguished from the high maintenancerequirements for centrifugal pumps due to well bottom debris thatcentrifugal pumps encounte adjacent the bottom of the well.

The invention is adapted for use at any site where liquid hydrocarbonshave accumulated underground because of the particular use of the site,which would be involved in such facilities as oil refineries, oil andgasoline storage and dispersing facilities, gasoline stations, and thelike; the invention is also applicable to recover hydrocarbons that haveseeped underground at the sites of pipe line leakage or breakage.

The depth of the cone of depression that will be required in the groundwater for any particular installation, and the amount of ground waterthat will have to be removed from the ground water table to create it,will be determined for any particular installation by such requirementsas the porosity of the soil, the apparent recoverable amounts ofhydrocarbons involved, the depth of the ground water table, and therequirements specified by the property owner and/or his consultant.Ground water removal that is effected to form the cone of depression mayalso be applied about the periphery of the cone of depression to inducemovement of the hydrocarbons into the cone, whereby the disposed ofground water would tend to flow back into the cone and in effect pushthe hydrocarbons ahead of it into the cone. This in effect would bemaking an "artificial recharge".

Further, where the hydrocarbon liquid body on top of the ground water isdeep enough, initially it may not be necessary to form a cone ofdepression in the ground water at a well to adequately recover theliquid hydrocarbons using a vessel 16 until the body of liquidhydrocarbons involved is reduced to the point where the cone ofdepression formation is required to keep up adequate performance.

The foregoing description and the drawings are given merely explain andillustrate the invention and the invention is not to be limited thereto,except insofar as the appended claims are so limited, since thoseskilled in the art who have the disclosure before them will be able tomake modifications and variations therein without departing from thescope of the invention.

What is claimed is:
 1. Apparatus for recovery of underground liquid froma well, said apparatus comprising:a vessel having a liquid receivingchamber, said vessel including a liquid inflow port at its lower end andliquid inflow permitting static pressure responsive check valve meansfor confining flow of the liquid through said inflow port to flow ofsame in an inflow direction into the vessel chamber, said vesselincluding an outflow conduit therein defining a liquid outflow inletport disposed adjacent and within the lower end of said chamber, saidconduit including liquid outflow permitting, static pressure responsivecheck valve means for confining flow of the liquid from said chamberthrough said outflow inlet port and said conduit to flow of same out ofsaid chamber, said conduit having an outlet adjacent to and exterior ofthe upper end of said vessel, a source of gas under pressure, piping forconveying the liquid from the well, said source of gas and said pipingbeing located externally of the well and adjacent the ground surfacelevel, conduit means connecting said gas source to said vessel chamberand including fluid directional flow control valve means locatedexteriorly of the well including directional control means for ventingsaid chamber to atmosphere therethrough and blocking off said gas sourceand forming the venting mode of said directional control valve means,and for communicating said gas source to said chamber free of venting ofsaid chamber to the atmosphere and forming the chamber staticpressurizing mode of said directional control valve means, pipe meansfor connecting said conduit outlet to said piping with a correspondingliquid head, means for suspending said vessel in the wells includingmeans for adjusting said vessel vertically in the wells and for holdingsame essentially stationary vertically with said inflow port thereof insaid liquid, and means for switching said directional flow control valvemeans between said modes for establishing alternate vessel operationcycles of liquid inflow to said chamber with venting of said chamber toatmosphere, opening of said vessel inflow valve means under the staticpressure of the liquid in the wells for flow of such liquid into saidchamber, and closing of said vessel outflow check valve means under thehead of said pipe means when such liquid is in said chamber, and gaspressurization of said chamber when such liquid is therein to evacuatethe liquid therefrom into said piping through said vessel outflow valvemeans and said pipe means under the static pressure of said pressurizedgas acting directly on the liquid in said chamber against said head ofsaid pipe means and free of venting of said chamber to atmosphere andmechnical pumping of the liquid, said switching means being exterior ofthe well and including means for selectively varying the time ofoperation of said operation cycles, said vessel at its lower end beingopen to define said inflow port, said inflow permitting check valvemeans being in said inflow port, said liquid inflow check valve meanscomprising a pair of oppositely acting, upwardly directed, flappermembers mounted for opposite free swinging movement about a common pivotaxis adjacent the lower ends of same and extending crosswise of thedirection of said inflow direction between a folded, substantiallyparallel, side by side inflow permitting relation in said vented mode ofsaid directional control valve means, and an angled inflow checkingrelation in said chamber static pressurizing mode of said directionalcontrol valve means, said liquid outflow check valve means comprising apair of oppositely acting, upwardly directed, flapper members mountedfor opposite free swinging movement about a common pivot axis adjacentthe lower ends of same and extending crosswise of the direction of saidoutflow direction between a folded, substantially parallel, side by sideoutflow permitting relation in said chamber static pressurizing mode ofsaid directional control valve means, and an angled outflow checkingrelation in said vented mode of said directional control valve means. 2.The apparatus set forth in claim 1 including;ballast means suspendedfrom said vessel lower end and spaced therefrom below same.
 3. Themethod of removing ground water, of a ground water table, at a wellextending below the ground surface level into the ground water table,said method comprising:disposing within the well and within the groundwater in the well, and adjacent the well bottom, a vessel defining achamber that is open at its lower end to freely receive the ground waterin the well adjacent the well bottom, admitting the ground water of thewell bottom into the chamber through its lower end, and venting toatmosphere air from within the vessel displaced by the quantity ofground water admitted to the chamber, and thereby establishing a vesselchamber charging step, and with the vessel being essentially stationaryvertically and at the same level as disposed at in said disposing step,sealing the vessel chamber off from the atmosphere and the ground waterthat is externally of the vessel and exposing the vessel chamber to asource of compressed air and conducting the quantity of ground watersolely under the static pressure of the compressed air applied directlythereto, and in an isolated flow that is free of mechanical pumping, toa ground level located point of disposal that is remote from saidvessel, and thereby establishing a vessel chamber discharge step, andwith the vessel being essentially stationary vertically and at the samelevel as said admitting step, and alternately repeating said vesselchamber charging and discharging steps while the vessel remainsessentially stationary vertically to effect step by step withdrawal ofthe ground water from the well bottom and in a timed sequence thateffects withdrawal of ground water from the well at approximately apredetermined rate.
 4. The method set forth in claim 3 wherein:thealternate charging and discharging steps create and maintain a cone ofdepression in the ground water table adjacent the well.